Conventionally, a combination weigher uses a plurality of weighing units each of which holds objects and weighs a weight of the objects held therein. Each weighing unit includes a weighing hopper which holds the objects for a specified time and discharges the objects and a load cell which supports the weighing hopper and weighs the weight of the objects inside the weighing hopper. As the load cell, for example, a Roberval-type load cell is used.
FIG. 4 is a perspective view showing a weighing unit of a first prior art example which is used in the combination weigher. This weighing unit includes a weighing hopper 53 and a load cell 51 supporting the weighing hopper 53. The weighing hopper 53 and the load cell 51 are arranged at both sides of a mounting fastener member 52 so as to sandwich the mounting fastener member 52 between them. The mounting fastener member 52 corresponds to a side wall portion of a center base body 17 (see FIG. 1) of the combination weigher. The load cell 51 is disposed inside of the center base body 17. The weighing hopper 53 is disposed outside of the center base body 17. A fastened portion 51a of the load cell 51 is fastened to the mounting fastener member 52 via a L-shaped support member 54. A movable portion 51b opposite the fastened portion 51a is coupled to the weighing hopper 53 via a coupling member 55 inserted into a through-hole 56 provided in the mounting fastener member 52.
In the weighing unit of the first prior art example, a stiffness of the L-shaped support member 54 must be increased to suppress reduction in weighing accuracy, and a size of the support member 51 must be increased. Accordingly, the present inventors proposed a weighing unit disclosed in Patent Literature 1 to suppress reduction in weighing accuracy, provide a compact configuration, etc. This weighing unit will be described as a second prior art example.
FIG. 5 is a side view showing a weighing unit of a second prior art example. In this weighing unit, also, a weighing hopper 63 and a load cell 61 are arranged at both sides of a mounting fastener member 62 so as to sandwich the mounting fastener member 62 between them. The mounting fastener member 62 corresponds to the side wall portion of the base body 17 (see FIG. 1) of the combination weigher. The load cell 61 is disposed inside of the center base body 17. The weighing hopper 63 is disposed outside the center base body 17. In this weighing unit, a fastened portion 61a of the load cell 61 is directly fastened to the mounting fastener member 62. One end of a coupling member 65 is fastened to an inner peripheral surface of a movable portion 61b of the load cell 61, while the other end thereof is coupled to the weighing hopper 63. The coupling member 65 is inserted into a through-hole 67 provided in the fastened portion 61a and a through-hole 66 provided in the mounting fastener member 62 and coupled to the weighing hopper 63.